I'm on Z68-M Pro with BIOS 3806 running a 3570K without issues.
looking at the info sheet I see two more BIOS updates available, just wondering if I should update the BIOS again to the latest
or just ride with what I have since it seems I have no issues (knock on wood..)

I hope I'm not breaking any forum rules here but I am getting no response on this issue on other parts of the site.

Currently my system is down (sig rig)

I had been experience random resets hanging boots (no POST) and after much forum reading and Googling, I've noticed that it is a defect in the ASUS motherboard line since the P67 chipset. I am very worried because too because it is possible that my CPU is damaged.

After much troubleshooting, based on recommendations found online for the problem, I have never managed to stay in the OS environment for more than a few hours. Then eventually not at all.

I initially got it booted, went into BIOS, switched to XMP under Ai Tweaker and it appeared to be fixed for like a day after that, then it started to reset randomly to the point where it no longer works and never boots up.

I reseated the CPU twice, and the board doesn't show any sign of overheating (I'm on liquid cooling).

not a CPU issue, just seems you have a buggy board.
now how it became buggy I take it your not sure but I doubt your CPU is the problem.
maybe also related to your latest BIOS flash or BIOS settings themselves..

what troubleshooting steps have you taken.?
cleared CMOS including pulling battery, defaulting BIOS from custom settings, tried a re-flash.?

not a CPU issue, just seems you have a buggy board.
now how it became buggy I take it your not sure but I doubt your CPU is the problem.
maybe also related to your latest BIOS flash or BIOS settings themselves..
what troubleshooting steps have you taken.?
cleared CMOS including pulling battery, defaulting BIOS from custom settings, tried a re-flash.?

I've done alot in the time i spent on it this past few weeks.

Here is what I did (NOT in any order)

Totally dismantled PC and checked stand offs - reinstalled components

Pulled each ram stick - tried each singly

reset CMOS

Enabled XMP in BIOS

Power on without USB devices plugged in

Pulled sound card

Swapped HDD

Enabled Hot-Pluggable on all SATA ports

Today:
I Desk run the board with another PSU..it powered on and i was in the BIOS just peering about for 5 minutes, decided to boot into OS - the problem started again. So my PSU doesnt appear to be the issue.

I will try the CPU on a friend's board, If it works I'm going to mourn the loss of the motherboard.

It confuses me because I never changed any hardware components since I acquired the system. This problem just erupted out of nowhere. It means an existing component just went bad. I have to deduce if it is CPU caused to know what my losses really are here.